A splotch in the cabinet

I saw it when I first walked through the house. It didn’t matter. I was already in love. I’d patch it up later. Later is now. I asked a very long and detailed question of Google then read enough of the responses before I got impatient to understand that vinegar will kill mold. I don’t know if it’s mold, but I had a spray bottle full of vinegar in the kitchen. Sprayed inside the cabinet. Cottage cheese ceiling started to crumble. Scraped that off. Scraped more off. Scrape it all off. Should have been wearing a mask. Put paper down first and was pretty proud of that. Cleaned the mess nicely. Can’t wait to hammer a piece of molding along that edge to block it off. First maybe a little bleach will help. Made a new spray bottle. Sprayed bleach all around that top shelf. Maybe should have cleared other shelves. Oh well. Eyes watering. Should probably have ventilation. Set up fan. Can’t wait to paint. Have a 5 gal container of Kilz that says Interior/Exterior. Well guess what Kilz, I got a job for you comin up.